Flip-top electronic devices such as notebook computers, mobile phones and the like generally have a display device and a host body pivotally coupled through a hinge. In general, the hinge mainly includes an axle and two connection members hinged on the axle to couple respectively with the display device and the host body. When in use the display device can be flipped against the host body in an unfolding state to perform operation as desired. When not in use, the display device can be folded over the host body in half. Through the hinge the size of the flip-top electronic device can be greatly shrunk to facilitate storing and carrying.
Conventional hinges, such as those disclosed in R.O.C. patent Nos. M493243, M492378, M471736 and M466462, mainly include a holding seat, two axles located abreast on the holding seat to couple respectively with a display device and a host body, and two torsional force generation assemblies corresponding respectively to one of the axles. Because the two axles are arranged abreast the hinge cannot be shrunk to a smaller size. As a result, the electronic device employed the hinge also cannot be thinned as desired. In addition, the torsional force generation assembly used on the conventional hinge is formed by stacking a plurality of elastic blades, and the tightness between the elastic blades is adjusted by wrenching an adjustment nut mounted onto the torsional force generation assembly, thereby provides a swivel torsional force to the axle. However, because the conventional structure deploys the torsional force generation assembly on one of the axles, during assembly each torsional force generation assembly requires torsional force adjustment. Such a practice cannot guarantee the two axles receiving same amount of torsional force during turning. Hence there is still room for improvement.